PROJECT SUMMARY Intimate partner aggression (IPA; physical, sexual, psychological) is a serious public health problem that affects more than one in three women in the United States. Although research on IPA among sexual minority women (SMW; lesbian, bisexual) is relatively new, research suggests that they may be at greater risk than heterosexual women. Given that alcohol use is a major contributing factor to IPA in heterosexual couples, and given findings (ours and others') demonstrating that SMW are substantially more likely than heterosexual women to drink alcohol, drink heavily, and to experience drinking- related problems, it is likely that alcohol plays an important role in IPA in SMW's relationships. However, there are large gaps in research on alcohol use and IPA among SMW. IPA research has historically taken a gendered perspective (women as victims/men as perpetrators) and for the most part has concentrated on either victims or perpetrators, not both. Research focused simultaneously on SMW and their partners can illuminate how individual- and couple-level factors operate outside the individualistic and gendered lens in this understudied and vulnerable population?and ultimately lead to culturally tailored interventions. Guided by a recent extension of the minority stress model to include the relational (couple-level) context of sexual minority stress, as well as the I3 (I-Cubed) theoretical perspective on IPA perpetration, we propose to collect individual and dyadic data to better characterize the links between hazardous drinking (HD) and IPA among SMW and their partners. The proposed project will draw from large and diverse cohort of SMW currently enrolled the Chicago Health and Life Experiences of Women (CHLEW)?a 19-year prospective study. The CHLEW focuses on understanding mechanisms linking minority sexual orientation and HD, defined in this study using several indicators such as heavy drinking, heavy episodic drinking, and intoxication. Specifically, we will recruit CHLEW participants and their partners to participate in the CHLEW Couples study. Thus, the proposed study offers an efficient and cost-saving opportunity to recruit a diverse sample that will contribute to understanding and ultimately reducing health disparities between SMW and heterosexual women. The aims of the project are to (1) examine associations among minority stress, HD and IPA in SMW and their partners; (2) examine potential mediators and moderators of the associations between minority stress and HD and IPA; and (3) guided by the I3 (I-cubed) theoretical perspective, test models that include effects of instigating factors (e.g., relationship conflict), impelling factors (e.g., minority stress, negative affect, trait anger), and inhibiting (e.g., relationship commitment, emotion regulation) or dis-inhibiting (e.g., HD) factors on IPA perpetration. This study builds on the Principal Investigator's unprecedented longitudinal study of SMW's alcohol use and its diverse sample and expands this unique program of research to explore the links between HD and IPA. Achieving the proposed aims will help fill important gaps in knowledge and will provide the basis for future research aimed at clarifying the causal pathways linking HD and IPA?which will, in turn, support the development of culturally appropriate individual and dyadic prevention and intervention strategies tailored to the needs of SMW.